Robertshaw and Dexen Standing Pilot Valve Troubleshooting

Robertshaw and Dexen make low-capacity millivolt gas valves for standing pilot fireplaces and gas logs. Empire, for example, fits a Dexen millivolt valve to its VFSR vent-free log burners, and we carry Dexen / Robertshaw replacement valves under several part numbers (listed below). The pilot's thermopile powers the valve, so it runs without house power, and Robertshaw publishes clear millivolt test values that work for a step-by-step diagnosis.

How to tell you have a Robertshaw or Dexen valve

Open the lower louver or control compartment door and look at the valve label.

• Robertshaw: a factory code in the 7000 family with "MV" (millivolt), such as 7000MVRLC, 7000MVRB-4-LC or 7000MVRB-5-LC, and a 710-5xx part number. The gas cock dial is marked OFF, PILOT and ON. Robertshaw lists the 710-503, 710-508 and 710-511 for fireplace and fireplace log control. Newer Robertshaw millivolt valves have one 1/4 in. and one 3/16 in. quick-connect terminal, so the wires only go back one way.
• Dexen: a 6003 series model. The 6003 is a millivolt valve used with a thermopile. The 6003S adds a quick drop-out safety magnet and works with a thermopile, an 11/32 in. thermocouple or an 8 mm thermocouple. The 6003KS adds a manual Hi/Low knob, and the 6003H has a built-in capillary thermostat.
• Part number from your parts list: we sell Dexen / Robertshaw valves under the numbers 060-500, 060-522, SRV23363, SRV24033, H2299, SV-6 and R3318. Those cross-references come from our own listings, not from a maker document, so match the number in your fireplace's parts list before ordering.

If your fireplace has a control module and a pilot that lights only when you turn it on, it is electronic (IPI), not millivolt. HHT's tip: a red or black piezo ignitor button in the control compartment means standing pilot. Dexen's 6003V series, for example, is an ignition-controlled valve, and HHT pairs a Dexen valve with its IntelliFire electronic ignition on the BCBV36. Use our IntelliFire troubleshooting guide for HHT IPI fireplaces instead. For a side-by-side of the brands, see fireplace gas valve types.

Thermopile only, or thermopile plus thermocouple?

These valves come in two setups, and a replacement must match yours:

• Thermopile only: the thermopile holds the pilot safety and opens the main valve. Robertshaw's 710-509 (propane) says "use two lead thermopiles only." Our 060-500, H2299 and SV-6 listings are thermopile-only, no turndown.
• Thermopile and thermocouple: a thermocouple holds the pilot safety and the thermopile opens the main valve. Robertshaw's 710-508 calls for a two-lead thermopile and a thermocouple and has a quick drop-out magnet. Our SRV24033 listing is this type, with 30% turndown.

Robertshaw designs its millivolt valves for its 1950 series two-lead thermopiles and says any two-lead thermopile with 250 to 750 mV output will work. For the difference between the two parts and how to test each, see our thermocouple and thermopile testing guide.

Millivolt checks with Robertshaw's values

Robertshaw numbers the three valve terminals 1, 2 and 3: the thermopile connects across 1 and 2, the wall switch or thermostat across 1 and 3, and the valve operator is between 2 and 3. Fireplace manuals usually letter the terminals instead: Empire's Dexen valve instructions put the thermopile on TH/TP and TP and the switch wires on TH/TP and TH. Use a meter with a 0 to 1000 mV range, make sure the connections are clean and tight, and leave the thermopile connected: Robertshaw's readings are all taken closed circuit.

Some fireplace manuals set their own numbers. HHT's BCBV36 manual, for example, asks for at least 350 mV from the thermopile and 8 to 16 mV from the thermocouple. If your owner's manual lists a value, use it.

What the readings tell you

• Operator reading over 100 mV but the valve does not open: Robertshaw says the valve operator has failed. Replace the operator or the valve.
• Operator reading under 100 mV: check the thermopile and the switch loss to find out why.
• Thermopile under 325 mV: clean and tighten every connection and adjust the pilot. If you cannot reach the minimum, change the thermopile.
• Switch loss over 80 mV: clean and tighten the switch wires, shorten them or use heavier wire, work the switch a few times to clean the contacts, or replace it. Robertshaw's maximum wire runs are 100 ft of 14 gauge, 64 ft of 16, 40 ft of 18, 25 ft of 20 and 16 ft of 22 gauge.

A quick switch test from HHT's manuals: place a jumper across the switch terminals. If the burner comes on, replace the switch. If not, jumper the switch wires at the valve; if the burner comes on now, the wires or connections are bad. More meter detail is in how to test a fireplace thermocouple and thermopile.

Pilot will not light or will not stay lit

1. Follow the lighting steps. Robertshaw: push in and turn the dial to OFF, set the switch to OFF, wait at least 5 minutes (10 for propane), turn to PILOT, push in and hold while you light the pilot, and keep holding about 1-1/2 minutes on millivolt models before letting go. If the pilot lights without pushing the dial in, replace the valve.
2. Check the flame. It should cover the upper 3/8 in. of the thermocouple or thermopile tip. Adjust it with the pilot adjustment screw, never with the gas cock dial.
3. Check the thermocouple nut. Start it by hand, run it all the way in, then add a quarter turn with a small wrench. Overtightening can damage the thermocouple or the magnet.
4. Test the thermocouple. Under 8 mV closed circuit, replace it.
5. Test the magnet. If the thermocouple reads over 8 mV and the pilot still drops out, watch the meter as the pilot goes out. Robertshaw says a good magnet stays locked until the reading has dropped 5 mV or more; if it lets go sooner, replace the valve. On thermopile-only valves, the magnet is good if it stays locked down to 120 mV or less.

A valve that has been under water in any way must be replaced. Turn the dial by hand only, never with pliers or a wrench, and never try to repair the gas control itself.

Pilot lit, main burner will not come on

1. Make sure the dial is at ON, not PILOT, and the switch, thermostat or remote is on.
2. Run the three readings above in order: operator (2 and 3), then thermopile (1 and 2), then switch loss (1 and 3).
3. Do the jumper test to separate the switch from the wiring.
4. If the thermopile and switch are good and the operator reads over 100 mV with no burner, the valve has failed. See how to replace a gas fireplace gas valve.

Flame height, Hi-Lo and propane conversion

Robertshaw's 710-503 and 710-511 have a Hi-Lo adjustment from 1.7 to 3.5 in. w.c. on natural gas, and Dexen lists a 1.7 to 3.5 in. natural gas and 5.5 to 10.0 in. propane setting range for its 6003S series, whose 6003KS has a manual Hi/Low knob. Fixed valves are factory set, natural gas at 3.5 in. w.c. Pressure adjustments are made with a manometer on the pressure tap and are a technician's job.

For propane, Robertshaw converts its 710 valves with a 1751 series regulator, using the 1751-013 for 11.0 in. w.c. propane, and the main burner and pilot orifices must be changed too. Use your fireplace maker's conversion kit when one is listed, and have a licensed gas technician do the work. Robertshaw rates its 710 valves for a maximum inlet pressure of 1/2 psi (14 in. w.c.).

Common part numbers and the fireplace-brand versions we sell

Parts for Robertshaw and Dexen valves

Find your symptom, check the usual cause, then the part. Confirm the part number in your owner's manual or parts list before ordering, and match gas type, turndown and the thermopile or thermocouple setup.

Shop by brand: all HHT (Heat & Glo, Heatilator, Quadra-Fire) parts.

FAQ

Are Dexen and Robertshaw fireplace valves the same?

Our catalog sells them as one family, and our Dexen / Robertshaw listings are described as exact replacements for the Robertshaw fireplace valve. Dexen's own product pages do not mention Robertshaw, so choose by the part number on your old valve or parts list, then match gas type, turndown and whether it uses a thermocouple.

How many millivolts should the thermopile make?

Robertshaw rates its millivolt valves for two-lead thermopiles with 250 to 750 mV output, and its test calls for more than 325 mV with the switch off. HHT's BCBV36 manual asks for at least 350 mV. If your owner's manual lists a value, use it.

Can I convert a Robertshaw fireplace valve to propane?

Robertshaw converts 710 series valves with a 1751 series regulator (1751-013 for 11.0 in. w.c. propane), and the burner and pilot orifices must be changed as well. Use the conversion kit your fireplace maker lists and have a licensed technician install it.

My fireplace says Dexen but has a control module. Is this guide for me?

No. A control module and a pilot that lights on demand mean an electronic (IPI) system. See the IntelliFire troubleshooting guide.

Related guides

• SIT 820 Nova millivolt valve troubleshooting
• How to test a fireplace thermocouple and thermopile
• All fireplace troubleshooting guides